393
FXUS61 KOKX 021737
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
137 PM EDT Thu May 2 2024
.SYNOPSIS...
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A frontal system will slowly work across the area by early this
evening. High pressure otherwise controls the weather through
most of Saturday. A cold front then moves through Sunday night
into Monday morning, then stalls south of the region. The front
moves back north as a warm front Tuesday into Wednesday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Low clouds continue to erode on the western side with the back
edge across western LI and coastal CT. Much of the area is
expected to become mostly sunny over the next 2 to 3 hours, the
possible exception is far eastern LI and coastal SE CT. These
areas could also clear out but then briefly see low clouds
reform until winds go northerly this evening behind the cold
front. Once again, forecast was updated to adjust temperatures
down, especially coastal locations of LI and CT. Some locations
along the immediate south shore and twin forks of LI and SE CT
may not get out of the 50s. However, locations from NYC north
and west still look to get into the upper 70s and lower 80s.
Patchy fog across CT and LI continues to burn off with very few
locations now a mile or less.
Warm front struggles to pass eastern locations this afternoon,
and may just get overtaken by the cold front this evening.
Continued dry for tonight as high pressure builds in from the
north. Low temperatures a few degrees above normal.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
High pressure continues to build in from the north while a ridge
axis aloft shifts towards us. Dry and cooler as winds arrive from
the east, limiting the mixing depth. Went slightly cooler than NBM,
which is close to its 25th percentile, and still might be a little
too warm based on progged 925mb temps of 7-8C.
Dry for Friday night and at least Saturday morning, but generally
lowering and thickening clouds are expected during this period. The
ridge axis aloft will be right over us during Saturday and slow to
move, so even Saturday afternoon stands a good chance of remaining
dry. Will maintain slight chance PoPs west of the Hudson River in
the afternoon. Mixing depth is limited once again for Saturday with
an onshore flow and the ridge axis aloft. Went slightly cooler than
the NBM again for high temps.
A cold front slowly approaches from the west Saturday night as it
runs into ridging aloft. Associated rainfall with the front will
also have a tough time pushing into the forecast area. Rain
probabilities remain below likely through the night.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Upper level ridge axis shifts offshore early Sunday and the flow
becomes near zonal by early next week. A longwave upper trough
across eastern Canada amplifies into the northeast Tuesday and moves
off shore Wednesday as another upper ridge builds to the west of the
area and moves into the region Wednesday. At the surface, a cold
front tracks across Sunday night into Monday, and becomes nearly
stationary as the flow becomes parallel to the boundary. A period of
some heavier showers will be possible Sunday as precipitable water
values increase to 1.3 inches. NBM QPF probabilities remain similar
to 24 hours ago. Probabilities of seeing 1 inch or more with this
event are 20 to 15 percent from west to east, with the 90th
percentile PQPF over 48 hours showing 1 to 1.5 inches, with the
higher values over the western half of the area.
Tuesday into Wednesday high pressure builds south from the Hudson
Bay region of Canada into the eastern Great Lakes. With a deep low
tracking northward from the northern plains into southern Canada
Tuesday into Wednesday the stalled cold front will move slowly
northward as a warm front. There is uncertainty as to the movement
of the front as high pressure, and an upper ridge will be in place.
Temperatures Friday night through Sunday will be around 5 degrees
above normal, and then Sunday night into Wednesday 5 to 10 degrees
above normal. For highs and lows Monday through Wednesday used a
blend of NBM and NBM 75th percentile to raise temperatures a few
degrees above the NBM. Depending on the movement of the warm front
next week, there is a chance that a few locations will have a record
high low Monday night into Tuesday morning.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
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A weak frontal system moves through the area this afternoon.
There is some uncertainty as to how quickly the associated cold
front gets through the area, which could lead to wind timing and
intensity issues. The front may struggle to get east of the
coastal terminals for a time.
Mainly VFR across city terminals but KJFK may still experience
IFR or MVFR ceilings for a few hours as a stubborn stratus deck
remains in close proximity to the airport. But even at KJFK it
is likely that status will dissipate. Further east it may take
until the late afternoon to see a return to VFR. Stratus may
reform eastern terminals later tonight and early on Friday but
its not expected to be as widespread.
S winds under 10kt gradually veering to west as a frontal
system attempts to work across the area. Gusts to 20 kt
possible. Coastal areas may remain onshore. By late day/early
evening, all the terminals should become more N/NE and E by
Friday morning.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments are likely as conditions improve.
OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday: VFR.
Saturday: Mainly VFR. Slight chance of showers and MVFR
conditions in the afternoon, increasing chances overnight.
Sunday...Likely showers, with MVFR or lower conditions. ESE
winds G15-20kt.
Monday...VFR.
Tuesday... Mainly VFR. Chance of MVFR showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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The Dense Fog Advisory was extended to 4 pm for the ocean
waters east of Fire Island Inlet and the eastern sound and
bays. This will likely need to be refined for timing based on
the progression and dissipation of the low clouds/fog the next
few hours. Cold front moving through the waters this evening
should be an end to the fog threat.
Winds will be at around 10 kt or less through the day today, but
will increase out of NE behind late tonight as high pressure builds
in behind a departed cold front. NE-E winds 10-15 kt Friday morning
with gusts below 25 kt diminish in the afternoon. A weak pressure
gradient then maintains sub-advisory conditions across the waters
Friday night through the middle of next week.-- End Changed Discussion --
&&
.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 4 PM EDT this afternoon for ANZ331-
332-340-345-350-353.-- End Changed Discussion --
&&
$$
UPDATE...DW
AVIATION...IRD